82 research outputs found
Sertoli cells are capable of proliferation into adulthood in the transition region between the seminiferous tubules and the rete testis in Wistar rats
Sertoli cells (SCs) play a crucial role in testis differentiation, development and function, determining the magnitude of sperm production in sexually mature animals. For over 40 years, it has been considered that these key testis somatic cells stop dividing during early pre-pubertal phase, between around 10 to 20 days after birth respectively in mice and rats, being after that under physiological conditions a stable and terminally differentiated population. However, evidences from the literature are challenging this dogma. In the present study, using several important functional markers (Ki-67, BrdU, p27, GATA-4, Androgen Receptor), we investigated the SC differentiation status in 36 days old and adult Wistar rats, focusing mainly in the transition region (TR) between the seminiferous tubules (ST) and the rete testis. Our results showed that SCs in TR remain undifferentiated for a longer period and, although at a lesser degree, even in adult rats proliferating SCs were observed in this region. Therefore, these findings suggest that, different from the other ST regions investigated, SCs residing in the TR exhibit a distinct functional phenotype. These undifferentiated SCs may compose a subpopulation of SC progenitors that reside in a specific microenvironment capable of growing the ST length if needed from this particular testis region. Moreover, our findings demonstrate an important aspect of testis function in mammals and opens new venues for other experimental approaches to the investigation of SC physiology, spermatogenesis progression and testis growth. Besides that, the TR may represent an important site for pathophysiological investigations and cellular interactions in the testis. © 2016 Taylor & Francis
Eruption of the lupine tooth in horses thoroughbred and campolina
Nos equinos, os primeiros dentes pré-molares da arcada superior, ou dentes lupinos, são pequenos e caracteristicamente vestigiais, mostram-se posicionados imediatamente mesiais à raiz do primeiro dente molar superior, não atuam funcionalmente na mastigação e podem ainda provocar dor no animal. Foram avaliados 63 animais da raça Campolina e 58 da raça Puro Sangue Inglês quanto à presença ou não de dente lupino. Os dados encontrados mostraram que 42,86% dos animais da raça Campolina apresentaram dente lupino, assim como 3,45% da raça Puro Sangue Inglês. A frequência variável encontrada revela que a presença deste dente é uma caracterÃstica particular e individual dos animais. Foi possÃvel observar através da aplicação do teste exato de Fisher (p_0,05) que entre os equinos das raças PSI e Campolina ocorreu diferença significativa (p_0,0001). De outra forma, para cada uma das raças a ocorrência da presença deste dente entre os sexos não foi observada diferença PSI (p_0,496) e Campolina (p_0,083). _________________________________________________________________________________ ABSTRACTIn horses, the first premolar teeth of the upper arch, or wolf teeth are small and characteristically vestigial, appear positioned immediately mesial to the root of the first molar tooth, do not act functionally in chewing and can also cause pain in animals. There were evaluated 63 animals of Campolina breed and 58 of Thoroughbred in relation to the presence or absence of wolf teeth. The findings showed that 42.86% of the Campolina horses presented wolf teeth, as well as 3.45% of the Thoroughbred. The variable frequency found discloses that the presence of this tooth is a particular and individual feature of animals. It was observed by applying the Fisher’s test (p<0.05) that among equine breeds Thoroughbred and Campolina, there was significant difference (p<0.0001). Otherwise for each of the breeds the occurrence of presence of this tooth among the genders was not observed Thoroughbred (p_0.496) and Campolina (p_0.083)
Dibutyl phthalate induced testicular dysgenesis originates after seminiferous cord formation in rats
Administration of dibutyl phthalate (DBP) to pregnant rats causes reproductive disorders in male offspring, resulting from suppression of intratesticular testosterone, and is used as a model for human testicular dysgenesis syndrome (TDS). DBP exposure in pregnancy induces focal dysgenetic areas in fetal testes that appear between e19.5-e21.5, manifesting as focal aggregation of Leydig cells and ectopic Sertoli cells (SC). Our aim was to identify the origins of the ectopic SC. Time-mated female rats were administered 750 mg/kg/day DBP in three different time windows: full window (FW; e13.5-e20.5), masculinisation programming window (MPW; e15.5-e18.5), late window (LW; e19.5-e20.5). We show that DBP-MPW treatment produces more extensive and severe dysgenetic areas, with more ectopic SC and germ cells (GC) than DBP-FW treatment; DBP-LW induces no dysgenesis. Our findings demonstrate that ectopic SC do not differentiate de novo, but result from rupture of normally formed seminiferous cords beyond e20.5. The more severe testis dysgenesis in DBP-MPW animals may result from the presence of basally migrating GC and a weakened basal lamina, whereas GC migration was minimal in DBP-FW animals. Our findings provide the first evidence for how testicular dysgenesis can result after normal testis differentiation/development and may be relevant to understanding TDS in human patients. © 2017 The Author(s)
Implant insertion angle and depth : peri-implant bone stress analysis by the finite element method
The study aimed to assess the influence of different implant insertion angles and depths on the stresses produced on the surface of peri-implant bone tissue under axial and oblique loading. The entire study followed the recommendations of the Checklist
Gene delivery to Nile tilapia cells for transgenesis and the role of PI3K-c2α in angiogenesis
Microinjection is commonly performed to achieve fish transgenesis; however, due to difficulties associated with this technique, new strategies are being developed. Here we evaluate the potential of lentiviral particles to genetically modify Nile tilapia cells to achieve transgenesis using three different approaches: spermatogonial stem cell (SSC) genetic modification and transplantation (SC), in vivo transduction of gametes (GT), and fertilised egg transduction (ET). The SC protocol using larvae generates animals with sustained production of modified sperm (80% of animals with 77% maximum sperm fluorescence [MSF]), but is a time-consuming protocol (sexual maturity in Nile tilapia is achieved at 6 months of age). GT is a faster technique, but the modified gamete production is temporary (70% of animals with 52% MSF). ET is an easier way to obtain mosaic transgenic animals compared to microinjection of eggs, but non-site-directed integration in the fish genome can be a problem. In this study, PI3Kc2α gene disruption impaired development during the embryo stage and caused premature death. The manipulator should choose a technique based on the time available for transgenic obtainment and if this generation is required to be continuous or not. © The Author(s) 2017
The Sertoli cell: One hundred fifty years of beauty and plasticity
Summary: It has been one and a half centuries since Enrico Sertoli published the seminal discovery of the testicular 'nurse cell', not only a key cell in the testis, but indeed one of the most amazing cells in the vertebrate body. In this review, we begin by examining the three phases of morphological research that have occurred in the study of Sertoli cells, because microscopic anatomy was essentially the only scientific discipline available for about the first 75 years after the discovery. Biochemistry and molecular biology then changed all of biological sciences, including our understanding of the functions of Sertoli cells. Immunology and stem cell biology were not even topics of science in 1865, but they have now become major issues in our appreciation of Sertoli cell's role in spermatogenesis. We end with the universal importance and plasticity of function by comparing Sertoli cells in fish, amphibians, and mammals. In these various classes of vertebrates, Sertoli cells have quite different modes of proliferation and epithelial maintenance, cystic vs. tubular formation, yet accomplish essentially the same function but in strikingly different ways. © 2016 American Society of Andrology and European Academy of Andrology
Validade e reprodutibilidade de dispositivos e aplicativos móveis para avaliar e monitorar a aptidão cardiorrespiratória de adultos: uma revisão sistemática
BACKGROUND: Traditionally, the assessment and monitoring of cardiorespiratory fitness is carried out indirectly, with few technological resources. Since the emergence and popularization of mobile electronic devices, this monitoring has also been carried out through these new resources. However, few portable devices are rigorously tested to identify their validity. OBJECTIVE: To develop a systematic review of the literature, seeking to identify the studies that carried out the validation and reproducibility of mobile devices and applications to assess and monitor cardiorespiratory fitness in adults. METHODS: Study of systematic literature review according to the methodological recommendations of The Cochrane Collaboration. The terms cardiorespiratory fitness, mobile devices, electronic device and adults were used to compose search syntaxes in the Web of Science, Scopus, LILACS – English; LILACS - Portuguese, SciELO, SciELO – Brazil and PubMed / MEDLINE databases, in languages portuguese, english and spanish. The temporal range of searches comprised the period from January 2015 to December 2019. RESULTS: A total of 3,396 studies were found from the initial searches. After applying the filters, 488 papers were selected for the reading of titles, of which 43 were included in the stage of reading abstracts. Nineteen studies were considered eligible for the full reading phase, of which, 09 were included in the present review. Regarding the validity of applications and devices, seven studies show satisfactory results regarding equipment data, indicating a high correlation between the results of the evaluated equipment and the comparative method, good accuracy of the equipment or validity of the generated data. On the other hand, two studies suggested prudence in the use of the equipment. CONCLUSION: The present review identified that there are few studies developed for the validation of mobile devices and applications aimed at monitoring cardiorespiratory fitness. Smartphone apps and smart clothes seem to be the most trusted resources to date.INTRODUÇÃO: Tradicionalmente a avaliação e monitoramento da aptidão cardiorrespiratória é realizada de forma indireta, com poucos recursos tecnológicos. A partir do surgimento e popularização dos dispositivos eletrônicos móveis, este monitoramento passou a ser realizado também por meio destes novos recursos. Entretanto, poucos dispositivos portáteis são testados de forma rigorosa para identificar sua validade.
OBJETIVO: Desenvolver uma revisão sistemática da literatura, buscando identificar os estudos que realizaram a validação e a reprodutibilidade de dispositivos e aplicativos móveis para avaliar e monitorar a aptidão cardiorrespiratória em adultos.Â
MÉTODOS: Estudo de revisão sistemática da literatura em acordo com as recomendações metodológicas da The Cochrane Collaboration. Os termos cardiorespiratory fitness, mobile devices, electronic device e adults foram utilizados na composição das sintaxes de busca nas bases de dados Web of Science, Scopus, LILACS – Inglês; LILACS - Português, SciELO; SciELO Brasil e PubMed/MEDLINE, nos idiomas português, inglês e espanhol. O intervalo temporal das buscas compreendeu o perÃodo de janeiro de 2015 até dezembro de 2019.
RESULTADOS: Um total de 3.396 estudos foram encontrados a partir das buscas iniciais. Após aplicados os filtros, 488 trabalhos foram selecionados para a leitura de tÃtulos, dos quais, 43 foram incluÃdos na etapa de leitura de resumos. Foram considerados elegÃveis para a fase de leitura na Ãntegra 19 estudos, dos quais, 09 foram incluÃdos na presente revisão. Em relação à validade dos aplicativos e dispositivos, sete estudos apresentam resultados satisfatórios referentes aos dados dos equipamentos, indicando alta correlação entre os resultados do equipamento avaliado e o método comparativo, boa precisão do equipamento ou validade dos dados gerados. Por outro lado, dois estudos sugeriram prudência no uso dos equipamentos.
CONCLUSÃO: A presente revisão identificou que existem poucos estudos desenvolvidos para a validação dos dispositivos e aplicativos móveis voltados ao monitoramento da aptidão cardiorrespiratória. Os aplicativos de smartphones e as roupas inteligentes parecem ser os recursos mais confiáveis até o momento
Successful xenogeneic germ cell transplantation from Jundia catfish (Rhamdia quelen) into adult Nile tilapia (Oreochromis niloticus) testes
Fish germ cell transplantation presents several important potential applications for aquaculture, including the preservation of germplasm from endangered fish species with high genetic and commercial values. Using this technique in studies developed in our laboratory with adult male Nile tilapias (Oreochromis niloticus), all the necessary procedures were successfully established, allowing the production of functional sperm and healthy progeny approximately 2 months after allogeneic transplantation. In the present study, we evaluated the viability of the adult Nile tilapia testis to generate sperm after xenogeneic transplant of germ cells from sexually mature Jundia catfish (Rhamdia quelen) that belong to a different taxonomic order. Therefore, in order to investigate at different time-periods post-transplantation, the presence and development of donor PKH26 labeled catfish germ cells were followed in the tilapia seminiferous tubules. From 7 to 20 days post-transplantation, only PKH26 labeled spermatogonia were observed, whereas spermatocytes at different stages of development were found at 70 days. Germ cell transplantation success and progression of spermatogenesis were indicated by the presence of labeled PKH26 spermatids and sperm on days 90 and 120 post-transplantation, respectively. Confirming the presence of the catfish genetic material in the tilapia testis, all recipient tilapias evaluated (n = 8) showed the genetic markers evaluated. Therefore, we demonstrated for the first time that the adult Nile tilapia testis offers the functional conditions for development of spermatogenesis with sperm production from a fish species belonging to a different order, which provides an important new venue for aquaculture advancement. © 2016 Elsevier Inc
Cause-specific mortality for 249 causes in Brazil and states during 1990–2015 : a systematic analysis for the global burden of disease study 2015
Background: Reliable data on cause of death (COD) are fundamental for planning and resource allocation priorities. We used GBD 2015 estimates to examine levels and trends for the leading causes of death in Brazil from 1990 to 2015. Methods: We describe the main analytical approaches focused on both overall and specific causes of death for Brazil and Brazilian states. Results: There was an overall improvement in life expectancy at birth from 1990 to 2015, but with important heterogeneity among states. Reduced mortality due to diarrhea, lower respiratory infections, and other infectious diseases contributed the most for increasing life expectancy in most states from the North and Northeast regions. Reduced mortality due to cardiovascular diseases was the highest contributor in the South, Southeast, and Center West regions. However, among men, intentional injuries reduced life expectancy in 17 out of 27 states. Although age-standardized rates due to ischemic heart disease (IHD) and cerebrovascular disease declined over time, these remained the leading CODs in the country and states. In contrast, leading causes of premature mortality changed substantially - e.g., diarrheal diseases moved from 1st to 13th and then the 36th position in 1990, 2005, and 2015, respectively, while violence moved from 7th to 1st and to 2nd. Overall, the total age-standardized years of life lost (YLL) rate was reduced from 1990 to 2015, bringing the burden of premature deaths closer to expected rates given the country’s Socio-demographic Index (SDI). In 1990, IHD, stroke, diarrhea, neonatal preterm birth complications, road injury, and violence had ratios higher than the expected, while in 2015 only violence was higher, overall and in all states, according to the SDI. Conclusions: A widespread reduction of mortality levels occurred in Brazil from 1990 to 2015, particularly among children under 5 years old. Major shifts in mortality rates took place among communicable, maternal, neonatal, and nutritional disorders. The mortality profile has shifted to older ages with increases in non-communicable diseases as well as premature deaths due to violence. Policymakers should address health interventions accordingly
Comparison of Anthropometric Profile and Cognitive Performance of Elite and Non-Elite Beach Volleyball Athletes
To compare the anthropometric profile and cognitive performance of elite and non-elite beach volleyball athletes. Comparative and descriptive study. The sample was composed by 8 athletes, divided in 2 groups: elite (n = 4) and non-elite (n = 4). They were evaluated in anthropometric parameters age, weight and height, and the variables of the cognitive performance evaluated by the battery of computerized tests CogState® (Brief Battery): Detection (Simple Reaction Time); Identification (Choice Reaction Time); One Back Speed (Working Memory); One Back Acuracy (Short Term Memory). Data were classified as non-parametric with the dispersion curve analysis performed by the Shapiro Wilk test. Anthropometric profile and cognitive performance variables were compared with the Mann Whitney U test between the groups. The procedures were performed with a significance level of p < 0.05 using the Statistical Package for the Social Science - SPSS®, Version 25.0. It was observed that there was significant difference in the anthropometric profile in the variable age (sig = 0.029) and in the cognitive performance significant differences occurred in the variables Detec (sig = 0.029) and Indent (sig = 0.029) of elite and not elite athletes of the beach volleyball modality. Elite and non-elite beach volleyball athletes present significant differences in the anthropometric variable (Age) and in the variables of cognitive performance (Detection and Identification) where elite athletes have a better cognitive performance than the non- elite athletes
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